The present invention pertains to rotary crankless machines of the type in which there is no crank shaft and in which the pistons are connected to a rotary shaft through cam means in such a manner that reciprocation of the pistons results in rotary movement of the shaft or vice versa. A number of devices of this general type are known in the art. All have the advantage that they tend to result in less vibration in a typical crank shaft type of reciprocating machine.
The problem with devices of this general type, however, is that it is difficult to provide a balanced mechanism which operates with relatively low frictional noise and is relatively compact.